Reliable and efficient compressors, such as centrifugal compressors, have been developed and are often utilized in a myriad of industrial processes (e.g., petroleum refineries, offshore oil production platforms, and subsea process control systems). In the centrifugal compressors, undesirably high levels of noise may be generated near regions of an impeller outlet and a diffuser inlet. For example, in the centrifugal compressor, process fluids may flow through the regions of the impeller outlet and the diffuser inlet at velocities sufficient to generate the high levels of noise. The noise generated may often have a frequency band in a frequency range that human ears may be sensitive to; and thus, may create an undesirable working environment for nearby operators. In addition to presenting a nuisance to the nearby operators, the noise may also result in unintended vibrations and structural damage of the compressors and/or components thereof.
In view of the foregoing, the compressors may often incorporate noise attenuators to reduce the high levels of noise. For example, external attenuators or devices, such as enclosures and wraps, may often be utilized to reduce the high levels of noise. Utilizing the external devices, however, often leads to increased overall cost as the external devices are often provided as an add-on for the already manufactured compressors. Further, the external devices reduce the high levels of noise by insulating structural components of the compressor, and not by reducing the generation and/or excitation of sound waves traversing along or through fluid passages of the compressors. Due to the limitations of the external devices, internal devices, such as acoustic liners or resonators, have been developed and are often disposed adjacent diffuser channels of the compressors to attenuate the noise generated by the process fluids. The acoustic liners may attenuate the high levels of noise by exploiting the Helmholtz resonance principle. For example, the sound waves generated by the process fluids may oscillate through perforations and/or cells formed in the acoustic liner fluidly coupled with the diffuser channels. The oscillation of the sound waves via the cells may dissipate the acoustic energy and thereby attenuate the noise. The acoustic liner may also attenuate the noise by providing a local impedance mismatch to reflect the acoustic energy upstream. While the acoustic liners may provide a viable option for attenuating the noise, current designs and/or methods for implementing or integrating the acoustic liners in the conventional compressors may be improved. For example, the acoustic liners are often integrated in the conventional compressors such that the cells of the acoustic liners present “dead volumes” to the process fluids flowing through the diffuser channels.
What is needed, then, is an improved system and method for integrating acoustic liners in a compressor, such that the acoustic liners exhibit increased or enhanced performance in reducing acoustic energy generated in the compressor by introducing a net or biasing flow through the acoustic liners.